Commit 91580f0d authored by Ard Biesheuvel's avatar Ard Biesheuvel
Browse files

ARM: head.S: use PC-relative insn sequence for secondary_data 



Replace the open coded PC relative offset calculations with adr_l
and ldr_l invocations. This removes some open coded arithmetic
involving virtual addresses, avoids literal pools on v7+, and slightly
reduces the footprint of the code.

Note that it also removes a stale comment about the contents of r6.

Reviewed-by: default avatarNicolas Pitre <nico@fluxnic.net>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent 172c34c9

arch/arm/kernel/head.S

+4 −15
Original line number Diff line number Diff line
@@ -383,10 +383,8 @@ ENTRY(secondary_startup) 
	/*

	 * Use the page tables supplied from  __cpu_up.

	 */

	adr	r4, __secondary_data

	ldmia	r4, {r5, r7, r12}		@ address to jump to after

	sub	lr, r4, r5			@ mmu has been enabled

	add	r3, r7, lr

	adr_l	r3, secondary_data

	mov_l	r12, __secondary_switched

	ldrd	r4, r5, [r3, #0]		@ get secondary_data.pgdir

ARM_BE8(eor	r4, r4, r5)			@ Swap r5 and r4 in BE:

ARM_BE8(eor	r5, r4, r5)			@ it can be done in 3 steps
@@ -401,22 +399,13 @@ ARM_BE8(eor r4, r4, r5) @ without using a temp reg. 
ENDPROC(secondary_startup)

ENDPROC(secondary_startup_arm)



	/*

	 * r6  = &secondary_data

	 */

ENTRY(__secondary_switched)

	ldr	sp, [r7, #12]			@ get secondary_data.stack

	ldr_l	r7, secondary_data + 12		@ get secondary_data.stack

	mov	sp, r7

	mov	fp, #0

	b	secondary_start_kernel

ENDPROC(__secondary_switched)



	.align



	.type	__secondary_data, %object

__secondary_data:

	.long	.

	.long	secondary_data

	.long	__secondary_switched

#endif /* defined(CONFIG_SMP) */

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